Computers can be digital, analogue or hybrid. The most common type, digital, are devices that can do all of the following: (1) store the processing program or programs and the data immediately necessary for the execution of the program; (2) be freely programmed in accordance with the requirements of the user; (3) perform arithmetical computations specified by the user; and (4) execute, without human intervention, a processing program that requires the computer to modify its execution, by logical decision, during the processing run. Analogue computers are capable of simulating mathematical models and comprise, at least, analogue, control and programming elements.

Peripherals are assemblies of components that are self-contained, but designed for use with computers. For purposes of classification, a peripheral must consist of more than a loaded circuit board. Peripheral equipment may be installed inside or outside the computer's housing. Important types of peripheral equipment are input-output devices, such as monitors, keyboards, mice and joysticks; storage devices, such as disk drives and CD-ROM readers; and printers. "Dumb" computer terminals, automated teller machines (ATM's), point-of-sale (POS) terminals and bar code scanners are treated as peripheral equipment.

Computers and peripheral equipment may be sold complete or in kits to be assembled by the purchaser.

The following activities involving printed circuit boards are undertaken in this industry: the production of the laminate material; the manufacture of the bare (rigid or flexible) printed circuit boards without mounted electronic components; and the loading of electronic components onto the boards.